Devices for cleaning the walls of bore holes



Aug. 2, 1955 A. E. ATKINSON DEVICES EOE CLEANING THE WALLS 0E EoEE HOLES Filed May 26, 1952 United States Patent() DEVICES FOR CLEANING THE WALLS F BORE HOLES Albert Edward Atkinson, Hinchley Wood, Esher, England Application May 26, 1952, Serial No. 290,055 Claims priority, application Great Britain .lune 26, 1951 8 Claims. (Cl. 166-173) This invention relates to devices sometimes known as scratchers for cleaning the walls of bore holes of the kind comprising a plurality of stili` wires or wire bristles carried by a ring or annular form of structure which is adapted to be mounted on the outside of the bore ho1e casing,'the wires extending outwardly from the said ring or like structure and being arranged so that by reciproeating the casing in the ho1e the wires exert a scratching action for cleaning the wall by the removal of caked mud or the like therefrom. These devices are primarily intended for removing caked mud from the bore hole immediately before the casing is cemented in the hole. The invention is more particularly concerned with devices of the above kind adapted for use with casing having enlarged or upset ends which necessitates a device which is divided or split longitudinally at one or more points to permit it to be sprung over or fitted round the casing between the enlargements. Such devices are usually welded together or secured by pin type joints after they have been fitted over the casing. The object of the present invention is to provide an improved device of simpler construction than those hitherto proposed or employed and which can be more easily and rapidly tted to the casing. A further object is to provide a more inexpensive construction which does not require the use either of welding or of pin type joints in vtting..

The invention comprises a longitudinally divided ring or structure the division edges of which are shaped tov interengage or to be connected by interengaging means in such a manner that they can be secured by displacement or deformation of the metal forming such shaped edges or means after the device has been fitted to the casing.

The invention also comprises arcuate elements, .for example a pair of half elements, constituting a ring like structure, in which the mating edges of the elements or of said elements and a connecting means are shaped like a folded or like interengaging joint and can be assembled by longitudinal sliding of the edges one into another,` the connection being capable of being secured by displacement or deformation of the metal as` by hammering.

According to a further feature of the invention, the interengaging or mating edges as defined in either of the two preceding paragraphs are of different longitudinal extent so that one fold portion is overlapped at both ends by another fold portion and the overlapping portions can be displaced or hammered down to` secure the connection against relative longitudinal motion of the parts. According to a further feature ofthe invention, the aforesaid overlapping portions are divided from the main part of the fold portion, e. g. by a saw cut, to facilitate displacement of said portions for securing the connection.

According to a further feature of the invention, the respective mating edges of the arcuate elements comprise inward and outward fold portions and the inward fold is` displaced or offset outwardly to lie` substantially in line with the main wall portion of the arcuate element, the elements being assembled by sliding the respective fold portions longitudinally one into the. other.

The cleaning wires may be of `any convenient kind and are secured in shaped cover elements which are welded to the ring structure.

The ring elements may be formed from thick sheet steel if desired by suitable bending or forming operations.

In the accompanying drawing,

Figure l is a perspective View of a bore hole cleaning device or scratcher constructed in accordance with the invention;

Figure 2 is a perspective view, to an enlarged scale, of the formed edges of half ring elements: constituting the body of the cleaning device or scratcher before assembly;

Figure 3 is a view similar to Figure 2 showing a modified mode of connecting the edges of the half ring elements.

In carrying the invention into eifect according to one convenient mode, a bore hole cleaning device or scratcher of the kind described comprises a pair of arcuate elements 1 and 2 of semi-circular shape which can be iitted together round the well casing and carrying the.` cleaning wires. Each element may conveniently be shaped from sheet steel of suitable thickness. The two longitudinal edges at opposite ends of the arcuate element 1 are bent outwardly and over to form a fold portion 3 lying parallel to the element wall and spaced therefrom a distance slightly greater than the thickness of the metal. The ends of the outwardly folded portion 3 are cut away for a short distance as shown in Figure 2. The longitudinal edges of the second element 2 are displaced outwardly or offset at 4 by an amount somewhat in excess of twice the thickness of the metal and the so displaced portion 5 is bent inwardly and rearwardly to form a fold portion aligned with the element wall 2 and defining a recess '7 into which the outward fold 3 of the element 1 can be introduced by relative longitudinal sliding of the respective elements 1 and 2. When so introduced, the outward fold 3 of one element lies within the outwardly displaced inward fold space 7 of the other element and forms a connection which can only be disengaged by sliding in the longitudinal direction of the folds, the connected elements being shown in Figure 1. The end portions 8 of the offset portion 5 of the element 2 are separated from the remainder by saw cuts 9 which are aligned with the cut away ends 10 of the fold 3 of the element 1.

The purpose of the saw cuts 9 and their alignment with the cut away ends of the fold 3 of element 1 when the elements 1 and 2 are aligned as indicated in Figure 2 is to enable the end portions 8 to be flattened, as by hammering for example, when the folds 6 and 3 are interengaged as later described. Thus when assembling the device, the fold 3 of element 1 is slidably :introduced into the fold 6 of element 2 until the saw cuts 9 are level with the ends 1t) of the fold 3. The outer faces of portions 8 are then flattened against tlie inner portions 6 so that they abut the ends 10 of fold 3 at both ends thereof. The engaged elements 1 and 2 are thereby locked against relative longitudinal movement.

The cleaning wires of the device are secured to the outside of the arcuate elements 1, 2 and one suitable mode of securing the wires is shown in Figure 1. The wire employed may be of any suitable character and in the present example wire of multiple strand or bundled form is employed.` Each wire 11 comprises a single length of wire folded into a narrow U or similar shape and the U portion is secured to the outside of the element by a cleat 12 consisting of a metal plate having formed in it a U-shaped recess 13 to receive the wire. The cleats are secured to the element by spot welding as indicated in Figure 1 or in any other desired manner. Each cleat 12 is secured in an inclined position upon the element so that the wires are inclined laterally with respect to the axis ofthe device and they are also inclined outwardly as shown. Thiinbles or short metal tubes i4 are secured over the wires where they emerge from the cover plates 6 substantially 12 and these tubes 14 are angled to direct the wires out- Wardly. Similar thimbles or tubes are secured near the outer ends of the wires and are also angled as shown. It will be understood however that other arrangements of lwires and wire securing means may be employed as is understood in devices of the kind in question.

The arrangement is such that when it is desired to mount the cleaning device upon a section of well casing, the two elements or halves 1 and 2 of the ring with the cleaning wires mounted thereon are placed around the casing one below the other and are engaged by sliding the outward folds 3 of one element into the inward folds 7 of the other element until the ends of the two elements are aligned. The previously described overlapping portions 5 of the inward fold, which are separated from the main body by saw cuts 9, are then displaced inwardly, preferably by hammering, into the spaces at the ends of the shorter outward fold 3, thereby securing the ring halves against relative longitudinal motion and also securing the completed device upon the casing. It will be seen that this mode of securing the ring halves is simple and capable of rapid execution, thereby saving time as compared with methods involving welding or the making of pin type joints. Also whilst the arrangement has especial advantages when applied to Well casing having enlarged or upset ends which preclude the use of solid rings, it can also be employed, if desired, with ordinary or standard casing. In such circumstances the usual stop means or lugs, which limit the longitudinal displacement of the cleaning device on the casing, can be welded upon the casing before the cleaning device is mounted thereon, and if desired before the casing is positioned for lowering in the bore hole.

In a modified mode of connection of the arcuate elements 1 and 2 as illustrated in Figure 3, each of the mating edges of the elements is formed with an outwardly directed fold portion 16, cach fold portion being similar to the other and being cut away to provide ends 17 which are spaced inwardly from the edges of the ring elements 1 and 2. A metal strip 1S of C-section is formed so that it can be slid over the aligned fold portions 16. Slits 19 are formed in the outer part of the strip 1S forming end pieces 2f) which are separated from the main outer part of the said strip. When the strip 18 has been fitted by sliding over the aligned fold portions 16 to connect the elements 1 and 2 together, the end portions 20 are flattened by hammering or otherwise and the connection is thereby secured.

The invention is not restricted to the example described above, since the details of the interengaging connection may be widely varied. Thus for example the interengageable fold portions may be of a sufficiently open character to allow of their being engaged directly without the necessity for longitudinal sliding, the connection being finally effected by hammering the fold parts together. Also the device may be divided at one point only and adapted to be opened and sprung over the casing, the connection being completed by hammering the fold portions together as mentioned above.

I claim:

l. A device or scratcher of the kind described for cleaning the walls of bore holes, comprising a longitudinally divided ring-like structure carrying the scratcher wires and means capable of constituting a folded joint between two adjacent division edges of said structure,

said means comprising a folded flange formation attached to one of said division edges and occupying a part only of the full extent of such division edge in the axial direction thereof, a folded flange formation attached to the other of said division edges and shaped to be interengaged with said first flange formation to constitute the joint between the said division edges, said second folded flange formation being shaped and arranged to extend also in an axial direction over a part of said first divi- Y sion edge not occupied by its associated flange formation when the division edges are aligned so that the portion of the said second flange formation which overlaps the said first flange formation is deformable relative to the latter to secure the joint against displacement in an axial direction.

2. A device according to claim 1, in which the said first and second folded flange formations are integral with the respective division edges of the ring-like structure.

3. A device according to claim 1, in which the said first and second folded flange are integral with the respective division edges, and the second folded flange formation overlaps both ends of the first folded flange formation so that the overlapping portions of said second flange formation are capable of being deformed to secure the joint.

4. A device according to claim l, in which the said rst and second folded flange formations are integral with the respective division edges, ,and the second folded flangeV formation comprises a main part coexteusive with the first folded flange formation and end portions which overlap the ends of the first folded flange formation, said end portions being provided with slits extending transverse to the division edges through part of the flange formation and aligned with the ends of said first flange formation, the said slits being arranged so that the end portions can be flattened by deformation to secure the joint.

' 5. A device according to claim l, in which the first of said folded flange formations extends outside and spaced from the ring-like structure, and the second of said folded flange formations lies substantially in line with the ring-like structure and is joined to the division edge thereof by a shoulder portion.

6. A device according to claim l, in which the said second flange formation comprises a member of flattened C-section affording a pair of oppositely folded edges one of which is engaged with the first said folded flange formation and the second folded edge of which is engaged with a folded flange formation integral with the second of the said division edges of the ring-like structure.

7. A device according to claim l, in which the said second flange formation comprises a member of flattened C-section affording a pair of oppositely folded edges one of which is engaged with the first said folded flange formation and the second of which is engaged with a folded flange formation integral with the second of said division edges of the ring-like structure, said C-section member having a'length and being arranged such that it overlaps both ends of said first flange formation.

8. A device according to claim 1, in which the said second flange formation comprises a member of flattened C-section affording a pair of oppositely folded edges one of which is engaged with the first said folded flange formation'and the second of which is engaged with a folded flangeformation integral with the second of said division edges of the ring-like structure, said C-section member having a length and being arranged such that it overlaps both ends of said first flange formation, said C-section member also being provided with slits extending transverse to the division edges through part of said member and aligned with the ends of said first flange formation, said slits being arranged so that the overlapping portions of the C-section member can be flattened by deformation to secure the joint.

References Cited in the fileV of this patent UNITED STATES PATENTS 296,786 Rock Apr. 15, 1884 540,827 Avery .lune ll, 1895 822,004 Kronauer May 29, 1906 2,506,405 Wright May 2, 1950 FOREIGN PATENTS 663,675 Great Britain Dec. 27, 1951 

